hdoj_1468解题报告

hdoj_1468解题报告

 

#include " iostream "
#include " string.h "
using   namespace  std;
// ------------------------------表达式单元-----------------------
// ---------------------------------------------------------------
struct  node  {
    int coe;//coefficient系数
    int fre;//frequency次数
    struct node *next;
} ;
// -------------------------------表达式----------------------------
// ------------------------------------------------------------------
struct  exp {//expression 链表实现——无表头
    struct node *head;
    int coe;
    int fre;//循环为N次的时候，coe=0,fre=1;为k次的时候，coe=k,fre=0;
    struct exp* plus(exp *a);
    void insert( struct node *x);
    void show();
} ;
struct  exp  *  exp::plus(exp  * a) {
    struct node *p,*q,*t;
    struct node h;
    p=head;
    q=a->head;
    t=&h;
    while(p && q){
        if(p->fre > q->fre ){
            t-> next=p;
            t = t->next;
            p = p->next;
        }
        else if(q->fre > p->fre ){
            t-> next = q;
            t = t-> next;
            q = q-> next;
        }
        else {
            p-> coe += q-> coe;//系数全为正
            t-> next = p;
            t = t-> next;
            p = p-> next;
            q = q-> next;
        }
    }
    if(p)    t-> next = p;
    else    t->next = q;
    head = h.next;
    return this;
}
void  exp::insert( struct  node  * x) {
    struct node h,*p;
    h.next = head;
    p = &h;
    while(p->next && p->next->fre > x->fre){
        p = p->next;
    }
    if(p-> next){
        if(p->next->fre == x->fre){
            p->next->coe +=x->coe;
        }
        else{
            x->next = p->next->next;
            p->next = x;
        }
    }
    else{
        p->next=x;
    }
    head = h.next;
}
void  exp::show() {
    //--------------------输出函数细节--------------------
    //(1)当为空链表是，表示时间为0
    //(2)系数为0的节点不要输出,全为0则表示总时间为0
    struct node *p;
    p = head;
    printf("Runtime = ");
    bool temp=0;
    while(p){
        if(p->coe==0){
            p = p->next;
            continue;
        }
        temp=1;
        if(p->fre==0){
            printf("%d",p->coe);
        }
        else{
            if(p->coe > 1){
                printf("%d",p->coe);
                if(p->fre != 0)
                    printf("*");
            }
            if(p->fre != 0)
                printf("n");
            if(p->fre > 1)
                printf("^%d",p->fre);
        }
        if(p->next)
            printf("+");
            
        p = p->next;
    }
    if(!temp)
        printf("0");
    printf("\n\n");
}
// ------------------------------操作符栈----------------------
// ------------------------------------------------------------
struct  operation_stack {//operation stack
    char op[1000];
    int top,base;
    //    struct node *p;
    void push(char x);
    char pop();
} ;
void  operation_stack::push( char  x) {
    op[ top++ ] =x;
}
char  operation_stack::pop() {
    return op[ --top];
}
// -----------------------------操作数栈----------------------
// -------------------------------------------------------------
struct  operand_stack {//operand stack
    struct exp * ra[1000];
    int top,base;
    void push(struct exp * x);
    struct exp *pop();
} ;
void  operand_stack::push( struct  exp  * x) {
    ra[ top++ ] = x;
}
struct  exp  * operand_stack::pop() {
    return ra[ --top];
}
// -----------------------------主函数--------------------------
// --------------------------------------------------------------
/**/ /*
讲每个代码换成运算式来作
数据处理举例
对于SAMPLE
我处理成#0+(<n> 0+4+(<3> 0+(<n> 0+1)+2)+1)+17#
左小括号后的中括号代表LOOP后的参数，最后用乘处理这个数
遇到')'也就是"END"就对前面的式子做一次处理计算出这个括号内的表达式值化成一个结果链表
*/
operation_stack    op; // 操作符栈
operand_stack    ra; // 值链表栈
int  a[ 1000 ],len; // LOOP值数组
int  main()
{
    int t,i,j,l=1;
    char o[10],order;
    struct node *p1;
    struct exp *p2,*p3;
    scanf("%d",&t);
    while(t--){
        op.top = op.base = 0;
        ra.top = ra.base = 0;
        len=0;
        while(scanf("%s",&o),strcmp(o,"BEGIN")) ;
        op.push('#');
        p2 = (struct exp *)malloc(sizeof(struct exp));
        p2->head=NULL;
        ra.push(p2);
        while(1){
            while(scanf("%s",&o),o[0]==0 || o[0]==32);
            //---------------CASE 1:------------------------
            if(strcmp(o,"LOOP")==0){
                scanf("%s",o);
                if(o[0]=='n')
                    a[len++]=-1;
                else{
                    j=0;
                    for(i=0;i<strlen(o);i++)
                        j=j*10+o[i]-'0';
                    a[len++]=j;
                }
                op.push('+');
                op.push('(');
                p2 = (struct exp *)malloc(sizeof(struct exp));
                p2->head=NULL;
                ra.push(p2);
            }
            //--------------CASE 2:---------------------------
            else if(strcmp(o,"OP")==0){
                scanf("%d",&i);
                p1 = (struct node *)malloc(sizeof(struct node));
                p2 = (struct exp *)malloc(sizeof(struct exp));
                p1->coe=i;    p1->fre=0;    p1->next = NULL;
                p2->head=p1;
                ra.push(p2);
                op.push('+');
            }
            //--------------CASE 3:----------------------
            else if(strcmp(o,"END")==0){
                while(1){
                    order = op.pop();
                    if(order == '#' || order == '(')    break;
                    p2 = ra.pop();
                    p3 = ra.pop();
                    p2->plus(p3);
                    ra.push(p2);
                }
                if(order=='('){
                    p2 = ra.pop();
                    if(!p2->head){
                        p2->head=(struct node *)malloc(sizeof(struct node));
                        p2->head->coe=1;
                        p2->head->fre=0;
                        p2->head->next=NULL;
                    }
                    p1 = p2->head;
                        
                    i=a[--len];
                    if(i>=0){
                        while(p1){
                            p1->coe*=i;
                            p1 = p1->next;
                        }
                    }
                    else{
                        while(p1){
                            p1->fre++;
                            p1 = p1->next;
                        }
                    }
                    ra.push(p2);
                    
                }
                if(order == '#'){
                    printf("Program #%d\n",l++);
                    p2=ra.pop();
                    p2->show();
                    break;
                }
            }
        }
    }
    return 0;
}